Revisited: Cave Shrimp
Taxonomy
Class: Malacostraca
Order: Decapoda
Family: Stenopodidae
Genus: Stenopus
Species: pyrsonotus
Description
The Cave shrimp is one of several members of the Stenopodidae (Stenopus meaning narrow footed) commonly available to aquarists. This genus is better known as the "Boxing Shrimp" due to their relatively large chelae (pinchers) on their third set of legs which are typically extended in front of their body in an open and ready to attack position.
Natural Habitat
The Cave shrimp is one of the more rare species of Stenopodidiae shrimp and generally found at depths over 30 feet. The Stenopus pyrsonotus has white legs, antennae, chelipeds (legs with pincers) and telson (tail). The abdomen is transparent with a red stripe down the back. Adults reach a maximum size of approximately 2 inches and live for well over 5 years, however most imported adults last only 1-3 years.
They are most commonly collected in the Hawaiian and the Marshall Islands, but can also be found in the waters of several other pacific island atolls. The shrimp typically occur in mated pairs in crevices and caves in the rock structure where they typically form cleaning stations. Using their curved long, white antennae they attract parasite infested fish to their dwelling to be cleaned. Once a host is ready, the shrimp use their chelae to remove and parasites and dead skin found on the body. Like most of the other Stenopods, the Cave shrimps primary hosts are Eels. In the wild, their primary food sources are the parasites and skin pulled from their hosts. Their secondary source of food is planktonic matter.
Aquarium Suitability
Due to its typical deep-water habitat the Cave shrimp is considered a moderately hardy shrimp, whereas most other members of the genus are very hardy. Some care must be taken to ensure an easy transition from its natural environment to a captive one. Like most other shrimp the Cave shrimp should be acclimated very carefully, as they are intolerant of sudden changes in salinity, pH, and temperature. They are also intolerant of higher levels of nitrates, copper, and phosphates. The aquarium should have ample room to prevent the Cave Shrimp from disturbing neighboring corals or anemones with its long antennae. Ideally, an under-hang or cave should be available as these shrimp prefer to spend their time upside down, clinging to the undersides of rocks.
Cave shrimp are generally peaceful, however they aggressively attack conspecifics and other smaller ornamental shrimp such as members of the Lysmata, Thor, and Perclimenes genus. They are excellent hunters of small bristle worms found within rocks and in the sand beds. As a general precaution it is not recommended to keep the Cave shrimp with smaller cohabitants as they can be opportunistic predators, catching smaller fish and shrimp. They are a scavenging carnivore and will take most meaty foods readily. Vitamin enriched frozen food is recommended to keep their vibrant colors and maintain their health.
There are many cases of the cave shrimp breeding in captivity however none of the young have reportedly been reared successfully. Larvae typically can not be provided an abundant food source and are typically too sensitive to poor water quality to be raised in most tanks. Moreover, the majority of the larvae would quickly be destroyed by the filtration and skimming equipment found in most of todays aquariums.
Care must be taken when netting the shrimp, especially with larger netting. The Cave shrimps body is covered with spiny hairs which can easily become tangled in netting. They may also abandon a large claw if startled or frightened. Fortunately, the lost appendage can re-grow after one or more successful molts; however, until then it will lack the capacity to defend itself. Iodine should be supplemented to facilitate the molting process.